The Apex Teton was designed and built by Pete Millett, a man with a long history of making awesome-sounding headphone amplifiers. His Web site is chock full of DIY audio projects and experiments for folks handy with a soldering iron. Millett sees himself as "a lifetime electronics geek, I got a ham radio license at the age of 8 and a first-class commercial radio license at 14." His passion for building great sounding gear runs deep.

The Teton may not win any beauty contests, but I admire its straight-ahead functionality. Millett builds his designs in his home near Dallas, Tex., with high-quality components sourced largely from the US and Japan. He builds one Teton at a time; it takes 10 hours to complete, measure and listen to each one.

The Teton will change the way you experience music over headphones. It's the aural equivalent of Technicolor, and the Teton makes other amps sound like black and white. Attention riveted, you savor the sound of old familiar and fresh tunes more completely than before. Returning to even the best solid-state amps flattens the sound, the separation between instruments diminishes, soundstage depth shrinks, and not just with acoustic recordings -- I noted the same contractions with Thom Yorke's "Atoms for Peace" CD.

I loved the Teton's way with music, but was it merely adding euphonic tube colorations to the sound? To find out, I compared the Teton to my Woo Audio WA6 Special Edition and Schiit Valhalla 2 tube headphone amps. No, the Teton was much better and clearer sounding than those two; it's a more advanced design. In fact, when I compared the sound of two well-regarded headphones -- the Hifiman HE-560 and the Sennheiser HD-700 -- with different amps, I always preferred the headphone that was plugged into the Teton.

That's really interesting. The differences in the sound signatures of headphones are generally stronger than those of amplifiers, but not this time. Designer Millett certainly doesn't claim the Teton is the perfect amp for every headphone, but it's at its best with high-impedance Sennheiser and Beyerdynamic headphones. I agree: my Beyerdynamic T-1 (600 Ohm) was the best-sounding headphone in my collection with the Teton. Millett feels the Sennheiser HD-800 (300 Ohm) is also a great match, but he also likes the sound of low-impedance Grado headphones with the amp.

Lucky me; I also have the fully solid-state Moon Neo 430HA digital converter/headphone amp in for review. It's great, but the Teton -- dare I say it -- adds more substance to the sound of recorded music. It's more flesh-and-blood alive, but the Neo 430HA is more accurate. The Moon Neo 430HA easily drives any headphone, including my Abyss AB-1266; the Teton cannot. If you crave hard-nosed accuracy, the Moon Neo 430HA is the one to get -- and it's also more affordable.

The Teton is a full-size amp and measures 17 x 7 x 11 inches (431 x 178 x 279 mm); it has three stereo RCA inputs, and one stereo RCA output (the Teton can be used as a stereo preamp and hooked up to a stereo power amp for speakers). The Teton has one 6.3mm headphone jack.

The Apex Teton sells for $5,000; the US distributor ships worldwide. (That price equates to about £3,211 in the UK and just over AU$6,000 at the current exchange rate.) Millett told me a healthy percentage of Tetons are sold in China and Singapore.